Eight factors, including forest coverage, fuel load, species composition, elevation, monthly mean temperature, monthly mean relative humidity, monthly mean wind velocity, and monthly mean precipitation of fire season,...Eight factors, including forest coverage, fuel load, species composition, elevation, monthly mean temperature, monthly mean relative humidity, monthly mean wind velocity, and monthly mean precipitation of fire season, were considered and the methods of weight, the cumulative probability, ARC/INFO technique, and raster-to-vector conversion were adopted in division of forest fuel type area. Firstly, the electronic maps of forest distribution and administrative divisions were built, then overlaid and transformed to the real-world coordinates. Finally, the forest fuel type areas of Heilongjiang Province including 81 counties were divided into five grades, accounting for 16%, 17%, 17%, 11%, and 38% respectively. The grade Ⅰ fuel type areas with highest fire danger rating mainly distributed on Daxinganling Mountains, Xiaoxinganling Mountains, and Zhangguangcailing Mountains, the grade Ⅴ fuel type areas mainly centralized on Songnen Plain, Sanjiang Plain, and other Plains, and other forest fuel type areas (grades Ⅱ, Ⅲ, and Ⅳ) were situated between plains and mountainous areas.展开更多
Mao抏rshan region is a representative natural secondary forested region in the eastern mountainous region, north-east of China. Under the support of ARC/INFO, the landscape pattern and landscape diversity of Maoerhsha...Mao抏rshan region is a representative natural secondary forested region in the eastern mountainous region, north-east of China. Under the support of ARC/INFO, the landscape pattern and landscape diversity of Maoerhshan region were studied by combining the forest type map (1:10000), which was drawn from the aerial photographs (1999), field investigation and land utilization map (1:10000). The selected indices included patch number, patch size, patch density index, richness index, dominance index, evenness index and diversity index. The results showed that the landscape dominant forest type in Mao抏rshan region was softwood broad-leaved forest. In all landscape types, the average patch area of natural secondary for-ests was bigger than that of artificial forest. The patch density index of each landscape formed in artificial forest was higher than that of natural secondary forest. The landscape diversity index and landscape evenness index of natural forest were highest, the landscape heterogeneity was also, but the landscape dominance was lower. In natural forest, the control effects of landscape elements on landscape-structure, function and its change were weakened. The artificial forest was on the contrary.展开更多
基金The paper was supported by National Nature Science Foundation of China (No.39870636).
文摘Eight factors, including forest coverage, fuel load, species composition, elevation, monthly mean temperature, monthly mean relative humidity, monthly mean wind velocity, and monthly mean precipitation of fire season, were considered and the methods of weight, the cumulative probability, ARC/INFO technique, and raster-to-vector conversion were adopted in division of forest fuel type area. Firstly, the electronic maps of forest distribution and administrative divisions were built, then overlaid and transformed to the real-world coordinates. Finally, the forest fuel type areas of Heilongjiang Province including 81 counties were divided into five grades, accounting for 16%, 17%, 17%, 11%, and 38% respectively. The grade Ⅰ fuel type areas with highest fire danger rating mainly distributed on Daxinganling Mountains, Xiaoxinganling Mountains, and Zhangguangcailing Mountains, the grade Ⅴ fuel type areas mainly centralized on Songnen Plain, Sanjiang Plain, and other Plains, and other forest fuel type areas (grades Ⅱ, Ⅲ, and Ⅳ) were situated between plains and mountainous areas.
文摘Mao抏rshan region is a representative natural secondary forested region in the eastern mountainous region, north-east of China. Under the support of ARC/INFO, the landscape pattern and landscape diversity of Maoerhshan region were studied by combining the forest type map (1:10000), which was drawn from the aerial photographs (1999), field investigation and land utilization map (1:10000). The selected indices included patch number, patch size, patch density index, richness index, dominance index, evenness index and diversity index. The results showed that the landscape dominant forest type in Mao抏rshan region was softwood broad-leaved forest. In all landscape types, the average patch area of natural secondary for-ests was bigger than that of artificial forest. The patch density index of each landscape formed in artificial forest was higher than that of natural secondary forest. The landscape diversity index and landscape evenness index of natural forest were highest, the landscape heterogeneity was also, but the landscape dominance was lower. In natural forest, the control effects of landscape elements on landscape-structure, function and its change were weakened. The artificial forest was on the contrary.